I have researched flour moisture and humidity matters quite extensively in the past since humidity is often blamed by people who end up with soupy doughs. As best I can tell, under normal conditions, it can take some time for humidity to affect the moisture content of a given flour. In this vein, you might be interested in this item by Tom Lehmann: http://www.pizzamaking.com/forum/index.php/topic,3433.msg29165.html#msg29165. This morning, I checked the humidity in Manheim, PA and also where I live in Texas, and the humidity is 85% in Manheim and 73% where I am in Texas. I suspect that our very small samples of flour, as compared with bags and especially 50-pound bags, are more susceptible to the effects of humidity, even in the short term. I plan to keep my last KABF sample at room temperature for several more days, and maybe even longer, to see if its moisture content changes.

As far as continuing to conduct future gluten mass tests is concerned, I am a big proponent of such tests. I think the ones that have already been conducted have amply shown their merit, in the sense that the gluten mass numbers for the different kinds of flours appear to be in the right pecking order, and even within the normal grouping of flours (e.g., high-gluten, bread, all-purpose, etc.). The gluten mass numbers might be higher than one might achieve using the Glutomatic machine because that machine centrifuges the samples onto a screen from which the gluten masses are extracted and weighed to arrive at a gluten index). But, as I noted before, I believe the relative values of the gluten masses are good enough for our purposes. For reverse engineering and cloning purposes, I think the gluten mass tests are among the best to use, along with the hydration bake tests. Knowing the moisture content of a flour is not a particularly useful test to me. Based on what Tom has said, that value will range from about 10-14%. That might affect some of the calculations I do, but I do not want to have to conduct flour moisture tests every time I want to do a calculation that involves the moisture content of the flour, especially since I tend to use fresh flours most of the time and, moreover, the calculations don't change that much with variations in flour moisture content.

Thanks for telling me and anyone else that might be interested that you have researched flour moisture and humidity matters quite extensively in the past and from your research it can take some time for humidity to affect the moisture content of a given flour. Tom Lehmannís reply from your link was interesting.

I have also saved my moisture content test and weighed it again when I returned home from market. It now weighs 19.30 grams so it is almost up to its original weight. This morning when I thought the weight had stabilized it really didnít.

Good to hear you think the gluten mass numbers are relative values and good enough for our purposes. Do you want me to start over to do gluten mass tests on the flours I have done the gluten mass tests on so far, or do you want me to do gluten mass tests on some other flours? I have Kyrol flour now that I could do a gluten mass test on if you want me to try that next.

I am not at all surprised to learn that storage of flour can affect flour and its gluten mass quantity, fornation and qualities. Marco did not specify those effects but I did a Google search and found a report directly on point at http://www.international-agrophysics.org/artykuly/international_agrophysics/IntAgr_2003_17_2_71.pdf. As you will note from that report, long storage of flour can have both positive and negative effects on gluten formation and its retention of moisture and its rheological properties (the gluten index test), as measured by the amount of water extracted during centrifugation. (It might help to note that the water retained by the gluten after extraction is called absorbed water and the water lost by extraction by centrifuge is called non-absorbed water). Moreover, the report noted that soft flours, of which I would consider the Caputo Extra/Blue 00 flour to be an example, actually had certain improved properties when used to make baked goods that made them better to use than stronger flours.

There is no way to know without further testing of a fresh batch of the Caputo Extra/Blue 00 flour whether the gluten mass you achieved from your gluten mass test was compromised by the long storage time. Since we noted in the Master gluten mass list that the Caputo Extra/Blue 00 flour has a 2010 date, that it the best we can do at this point.

As for repeating past gluten mass tests, thank you for offering, but I am not sure what that would do for us. Your flours seem to be fairly fresh. Anyone conducting a gluten mass test will be at the mercy of the flour as it is constituted as of the time the test is conducted. If flour age is a factor in gluten formation, then that might show up in the gluten mass quantity and quality, depending on the particular flour in question and other factors.

I forgot that you have the Kyrol high-gluten flour. If you don't mind doing a gluten mass test on that flour, I would be interested in the results.

As a footnote, when I was researching the effects of storage on flour, I also learned that some of the vitamins added to flour also degrade with long storage of the flour. I believe that there are also changes in the lipids in flour. All of this serves to instruct us to use flour while it is fresh to get the best results and the fullest benefits.

I am not at all surprised to learn that storage of flour can affect flour and its gluten mass quantity, fornation and qualities. Marco did not specify those effects but I did a Google search and found a report directly on point at http://www.international-agrophysics.org/artykuly/international_agrophysics/IntAgr_2003_17_2_71.pdf. As you will note from that report, long storage of flour can have both positive and negative effects on gluten formation and its retention of moisture and its rheological properties (the gluten index test), as measured by the amount of water extracted during centrifugation. (It might help to note that the water retained by the gluten after extraction is called absorbed water and the water lost by extraction by centrifuge is called non-absorbed water). Moreover, the report noted that soft flours, of which I would consider the Caputo Extra/Blue 00 flour to be an example, actually had certain improved properties when used to make baked goods that made them better to use than stronger flours.

There is no way to know without further testing of a fresh batch of the Caputo Extra/Blue 00 flour whether the gluten mass you achieved from your gluten mass test was compromised by the long storage time. Since we noted in the Master gluten mass list that the Caputo Extra/Blue 00 flour has a 2010 date, that it the best we can do at this point.

As for repeating past gluten mass tests, thank you for offering, but I am not sure what that would do for us. Your flours seem to be fairly fresh. Anyone conducting a gluten mass test will be at the mercy of the flour as it is constituted as of the time the test is conducted. If flour age is a factor in gluten formation, then that might show up in the gluten mass quantity and quality, depending on the particular flour in question and other factors.

I forgot that you have the Kyrol high-gluten flour. If you don't mind doing a gluten mass test on that flour, I would be interested in the results.

As a footnote, when I was researching the effects of storage on flour, I also learned that some of the vitamins added to flour also degrade with long storage of the flour. I believe that there are also changes in the lipids in flour. All of this serves to instruct us to use flour while it is fresh to get the best results and the fullest benefits.

Peter

Peter,

I find that article you referenced on storage of flours very interesting. I see one of the results indicated that different effects of wheat storage had to do with different wheat cultivars and saw where the lower protein flour faired better in its ability to absorb water and a better forming gluten structure. I wonder if I try some of my old Caputo Extra/Blue flour on my Caputo thread in a home oven how it would fair. I purchased the Caputo Extra/Blue flour at an Italian grocery store in Lancaster, but donít think they handle it anymore. I might have to call them and see if they now carry the Caputo Extra/Blue to do another gluten mass test. The lower protein flour also showed the trend of the gluten to strengthen the rheological properties as the storage of the flour increases. The higher gluten flour loses its absorption properties faster.

I didnít know that some of the vitamins added to flour also degrade with long storage of flours. I have so many flours and might need to get rid of some of them because some of them might have outlived their flour lives. I understand now that having all the flours that I have at home is not a good idea.

I will do the gluten mass test on the Kyrol high-gluten flour later this week. I also have Occident flour that is bromated if you want me to do a gluten mass test on it.

Thank you for conducting the gluten mass test on the Kyrol high-gluten flour. I have updated (below) the Master list to include the Kyrol flour. I believe that the Kyrol flour is 13.8 +/- 0.3% protein. If that turns out not to be right, I will correct the Master list.

You are correct about variances in protein content from region to region. There are many factors that come into play from a flour protein content standpoint. These include the wheat cultivar, the growing area, the growing season, the weather and the time of harvest. Millers try to adjust for these factors as best they can through blending of different flours, with the objective of delivering a product to the end user that does not differ materially over the course of the year. Of course, there are limitations to this since so many factors are beyond the miller's control. Fortunately, in the U.S., we are amazingly blessed from a geographical standpoint. The American Midwest, where wheat and many other crops are grown, is the world's largest contiguous piece of farmland. So, we have choices and options that no other country in the world has.

Thanks for posting more about variances in protein content from region to region and what factors come into play.

On another note, I think I am going to throw away my moisture hydration test with the Caputo Extra/Blue flour. For awhile the weight kept changing and was around 19.35 grams. Today since it is fairly humid in our area the weight of the hydration test with the Caputo Extra/Blue flour is 19.47 grams. I guess flour can become heavier in ambient moisture than it originally was.

Either tonight or tomorrow I would do the gluten mass test on the Occident Bleached Bromated flour. I have no idea what protein content that flour has.

The gluten mass test was done on the Occident Bleached Bromated flour this morning using the same methods as before. The weight of the gluten mass test after washing was 2.7 ounces.

This seems like an alternative way to wash out all the starches or other substances in flour.

How to separate the gluten from wheat flour. First you must wash out all the starches from a mixture of flour and water as follows:1. Mix a small amount of flour (about 8 ounces) with just enough water to form a stiff ball of dough.2. Soak the ball of dough in water for about 30 minutes.3. Over a fine mesh sieve, and under running water from a faucet, wash out all the starch. When all the starch has been removed the water will run clear.http://thebakerynetwork.wordpress.com/2011/01/11/baking-and-baking-science/

I wonder if that method might work better or the same as the method that is being used.

Sometime I would like to separate glutenin and gliadin from gluten to if that works.

Once you have washed out the starches, you end up with raw wet gluten. If you soak the ball of gluten in pure ethyl alcohol, the glutenin and the gliadin will separate out. The gliadin is the sticky part and will form long tiny silky looking strands when touched with the finger. The glutenin on the other hand will look and feel like tough raw rubber.

I also have Pillsbury bread flour and King Arthur cake flour at home, but donít think too many members used those flours for making pizzas, so there probably wouldnít be any use doing gluten mass tests on them.

Sometime I would like to separate glutenin and gliadin from gluten to if that works... If you soak the ball of gluten in pure ethyl alcohol, the glutenin and the gliadin will separate out.

Norma,I know this method is used for raw flour, but I am not entirely sure that this method would work once the gluten molecule has been formed. The two molecules are covalently joined by a disulphide bridge, which typically needs an enzyme or a low pH to break the bond. If you would like, I can review the literature tonight to see if their is a feasible and observable method for extracting the two subunits once the molecule has been formed. Otherwise, given the weight of the gluten mass, assuming it is 100% pure gluten, I could calculate the molecular weights of both subunits and apply it to your recorded weight to give you a crude idea of how much glutenin and gliadin are in your gluten masses.

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Thank you for doing the gluten mass test on the Occident flour. I have added the gluten data on that flour to the Master list as updated below. Can you confirm that the Occident flour you have is bleached and bromated and, by any chance did you weigh the Occident gluten mass in grams also? As noted below, the Occident and KABF numbers are running neck in neck as they approach the finish line.

According to Dave (dmcavanagh), he was informed by ConAgra that the Occident flour has a protein content of 12.4%.

There is really no way to know whether the alternative gluten mass test would produce better results. You could well end up with a second set of numbers, and they might display the same pattern as shown in the above Master list, but there would be no way to conclude which set is the better one.

With respect to the Pillsbury bread flour and the King Arthur cake flour, I would be curious to know their respective gluten mass values. We do have some members who use the Pillsbury bread flour (it is also the one that Tom Lehmann regularly recommends), and it would be interesting to see how much gluten is in cake flour in relation to the values given above. I will leave to you to decide if you want to do gluten mass tests on those two flours.

Norma,I know this method is used for raw flour, but I am not entirely sure that this method would work once the gluten molecule has been formed. The two molecules are covalently joined by a disulphide bridge, which typically needs an enzyme or a low pH to break the bond. If you would like, I can review the literature tonight to see if their is a feasible and observable method for extracting the two subunits once the molecule has been formed. Otherwise, given the weight of the gluten mass, assuming it is 100% pure gluten, I could calculate the molecular weights of both subunits and apply it to your recorded weight to give you a crude idea of how much glutenin and gliadin are in your gluten masses.

Jim,

I would be interested in knowing if the method I posted would work once the gluten molecule has been formed. I didnít know anything about that the two molecules being joined and then they would typically need an enzyme or a low pH to break the bond. If it isnít too much bother for you, and you have time to review the literature to see if this might be a feasible and observable method for extracting the two subunits once the molecule has been formed, I would appreciate what you think. Thanks for the help!

Thank you for doing the gluten mass test on the Occident flour. I have added the gluten data on that flour to the Master list as updated below. Can you confirm that the Occident flour you have is bleached and bromated and, by any chance did you weigh the Occident gluten mass in grams also? As noted below, the Occident and KABF numbers are running neck in neck as they approach the finish line.

With respect to the Pillsbury bread flour and the King Arthur cake flour, I would be curious to know their respective gluten mass values. We do have some members who use the Pillsbury bread flour (it is also the one that Tom Lehmann regularly recommends), and it would be interesting to see how much gluten is in cake flour in relation to the values given above. I will leave to you to decide if you want to do gluten mass tests on those two flours.

Peter

Peter,

I will have to try and call the Country Store to confirm that the Occident flour that I have is unbleached and bromated. It says that on the labeling, but I am not sure. I didnít weigh the Occident gluten mass in grams. I see the Occident and KABF numbers are running neck to neck to the finish line.

When I find time next week I will do the gluten mass tests on the Pillsbury bread flour and the King Arthur cake flour, since you think those values might have some use.

Norma,Well, after an extensive search I have good news and bad news. While it is possible to isolate the concentration of the glutenin and gliadin from your wet gluten mass, it would not be financial feasible for you to pursue this route any further. B/c both molecules are water soluble in isolation, you would need a mass spectrometer to isolate the precise quantities of both glutenin and gliadin contained in your gluten mass. I know at KUMC it costs myself close to $400 per sample to run something through the machine and brand new machines cost $50,000.00 and up to $400,00.00. Sorry

« Last Edit: March 23, 2012, 08:34:29 PM by JimmyG »

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Norma,Well, after an extensive search I have good news and bad news. While it is possible to isolate the concentration of the glutenin and gliadin from your wet gluten mass, if would not be financial feasible for you to pursue this route any further. B/c both molecules are water soluble in isolation, you would need a mass spectrometer to isolate the precise quantities of both glutenin and gliadin contained in your gluten mass. I know at KUMC it costs myself close to $400 per sample to run something through the machine and brand new machines cost $50,000.00 and up to $400,00.00. Sorry

Jim,

Thanks for doing an exhaustive search and finding that it is possible to isolate the concentration of the glutenin and gliadin from a wet gluten mass. I can understand after you post it would be too expensive to pursue it further. I just wanted to see what the glutenin and gliadin would look like after they are separated from any dough. Maybe I will look on Google images to see if there are some pictures.

You sure donít have to say you are sorry, you are always a help with the knowledge you have.

The gluten mass test was done on a 9 ounce dough ball this morning using Pillsbury Bread Flour. I used the same methods as before and did the test on the dough ball under cold running water. The weight of the gluten mass test was 63.60 in grams or 2.243 in ounces.

I had also taken the last gluten mass test and placed it in plain isopropyl alcohol (rubbing alcohol)-(right after I did the last gluten mass test) to see if somehow the gliadin and glutelin could be separated with just using the isopropyl alcohol. I didnít try pure ethyl alcohol because I didnít have any. I sure donít know, but when I checked on it today it looks like the gliadin and glutelin separated at least where I could scrap the gliadin from the rubbery glutelin. I donít know if anyone thinks I should attempt to scrap the gliadin off and weigh it, but it does comes off with just scrapping with my fingers. These are two pictures of how the gluten mass test looks in the isopropyl alcohol. The gliadin does feel sticky and the glutenin sure looks rubbery.

Thank you for conducting the gluten mass test on the Pillsbury bread flour. Was it the Pillsbury Best bread flour as shown at http://www.pillsburybaking.com/products/details/719? If so, that is the first bread flour whose gluten content falls in with all-purpose flour instead of bread flour. As is often the case with supermarket flours, it is hard to get solid information on the Pillsbury bread flour. There is some information provided in the Nutrition Facts, but with rounding factors it is hard to get accurate numbers. Pillsbury at the supermarket level is now owned by J.M. Smucker (General Mills sells Pillsbury branded flours to professionals). I may try to see if I can more information from Smucker.

Also, can you tell me whether the Pillsbury bread flour you have is bleached? The Smucker website for the Pillsbury flour notes only the all-purpose flour as being unbleached.

Thank you for conducting the gluten mass test on the Pillsbury bread flour. Was it the Pillsbury Best bread flour as shown at http://www.pillsburybaking.com/products/details/719? If so, that is the first bread flour whose gluten content falls in with all-purpose flour instead of bread flour. As is often the case with supermarket flours, it is hard to get solid information on the Pillsbury bread flour. There is some information provided in the Nutrition Facts, but with rounding factors it is hard to get accurate numbers. Pillsbury at the supermarket level is now owned by J.M. Smucker (General Mills sells Pillsbury branded flours to professionals). I may try to see if I can more information from Smucker.

Also, can you tell me whether the Pillsbury bread flour you have is bleached? The Smucker website for the Pillsbury flour notes only the all-purpose flour as being unbleached.

Peter

Peter,

The Pillsbury Best bread flour I used for the gluten mass test is the one you posted in your link. I donít think I can find on the bag if the flour is unbleached or not. I just looked and I canít tell. What would I look for other than the words bleached or non-bleached? All I see is something on the side of the bag that says: Pillsbury Best Bread flour is made from hard spring wheat and contains a higher percentage of protein than regular All Purpose Flour. It also goes on How to Use Bread Flour? Bread Flour is ideal for bread making and can be directly substituted for All-Purpose Flour. It then goes on to say it combines well with Whole Wheat and Rye flours. If you want any other information from the bag, let me know.

Do you think I should throw the gluten mass test away that was in the isopropyl alcohol, or do you think it would be any good for any tests?